Highly Sensitive Multi-Channel IDC Sensor Array for Low Concentration Taste Detection

Abstract

In this study, we designed and developed an interdigitated capacitor (IDC)-based taste sensor array to detect different taste substances. The designed taste sensing array has four IDC sensing elements. The four IDC taste sensing elements of the array are fabricated by incorporating four different types of lipids into the polymer, dioctyl phenylphosphonate (DOPP) and tetrahydrofuran (THF) to make the respective dielectric materials that are individually placed onto an interdigitated electrode (IDE) via spin coating. When the dielectric material of an IDC sensing element comes into contact with a taste substance, its dielectric properties change with the capacitance of the IDC sensing element; this, in turn, changes the voltage across the IDC, as well as the output voltage of each channel of the system. In order to assess the effectiveness of the sensing system, four taste substances, namely sourness (HCl), saltiness (NaCl), sweetness (glucose) and bitterness (quinine-HCl), were tested. The IDC taste sensor array had rapid response and recovery times of about 12.9 s and 13.39 s, respectively, with highly stable response properties. The response property of the proposed IDC taste sensor array was linear, and its correlation coefficient R2 was about 0.9958 over the dynamic range of the taste sensor array as the taste substance concentration was varied from 1 μM to 1 M. The proposed IDC taste sensor array has several other advantages, such as real-time monitoring capabilities, high sensitivity 45.78 mV/decade, good reproducibility with a standard deviation of about 0.029 and compactness, and the circuitry is based on readily available and inexpensive electronic components. The proposed IDC taste sensor array was compared with the potentiometric taste sensor with respect to sensitivity, dynamic range width, linearity and response time. We found that the proposed IDC sensor array has better performance. Finally, principal component analysis (PCA) was applied to discriminate different types of taste of the mixed taste substances.

Simple fabricating PCB-based inter digital capacitor for glucose biosensor

“…Figure 4 shows the measurement of RCL meter. On various molars of glucose media (2,4,6,8, and 10 M, the capacitance value of IDC was slightly increased until 0.58 F (25 patterns of IDC). However, the resistance of IDC sensor fluctuated.…”

“…There are many techniques for developing biosensor including colorimetry, conductometry, electrochemistry, fluorescent spectroscopy, optics, and interdigital capacitor (IDC) method [2]. The relative permittivity or capacitance changing of sensor has been used as a measurement parameter for IDC method.…”

“…The relative permittivity or capacitance changing of sensor has been used as a measurement parameter for IDC method. Its technique has successfully implanted as biosensor [1,2], water level sensor [3], soil moisture [4], electronic tongue/taste [5], and bacterial monitoring [6].…”

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

“…The pulse generator/modulation [47,48,49] unit consists of three units: a square-wave generator, a buffer amplifier, and a laser diode (LD) driver with LD. The square-wave generator produces a square wave with a frequency of 10 kHz and a 50% duty cycle.…”

Interdigitated Sensing and Electrochemical Impedance Spectroscopy

“…The planar structure of the developed electrodes formed prototypes for single-sided and non-invasive measurements. Figure 3.1 shows the working principle of the designed electrodes (Khan and Kang 2015). When a frequency-depended voltage signal is applied to the excitation electrode, a resultant electric field is generated between the two oppositely charged electrodes.…”